Novel disulfides derived from 1,2,4-thiadiazole

ABSTRACT

3-Halo-1,2,4-thiadiazolyl 5-disulfides and 1,2,4-thiadiazolyl 3,5-bis(disulfides) are prepared by reaction of mercaptans with the corresponding sulfenyl chlorides. The disulfides are useful as corrosion inhibitors in lubricants.

o Unite States atem 1191 1111 3,904,537 Ripple 1 Sept. 9, 1975 NOVEL DISULFIDES DERIVED FROM [56] References Cited I,Z,4-THIADIAZOLE UNITED STATES PATENTS [75] Inventor: David Eugene Ripple. Willoughby 2,719,125 9/1955 Roberts 252/47 X Hills, Ohio 3,663,561 5/1972 Blaha 252/47 [73] Assignee: The Lubrlzol Corporation, Primary Examiner Delben E Gamz Cleveland, Ohio Assistant Exammerl. Vaughn [22] Filed: Feb. 22, 1974 Attorney, Agent, or Firm-James W. Adams, Jr.; 1 pp No: 444,623 William H. Pittman Related U.S. Application Data 57 A S T [62] Division of Ser. No. 249,806, May 3, 1972, Pat. No. 3 2 4 1 5 diSu|fideS and 1,24

332L236 thiadiazolyl 3,5-bis(disulfides) are prepared by reaction of mercaptans with the corresponding sulfenyl [52] 252/47'5; 252/47 252/391 chlorides. The disulfides are useful as corrosion inhibi- [51] Int. Cl. Cl0m l/58; ClOm 3/32 tors-in lubriamw [58] Field of Search 252/47, 47.5, 391

7 Claims, No Drawings NOVEL DISULFIDES DERIVED FROM 1,2,4-THIADIAZOLE More particularly, it relates to compounds having the formula Methyl Benzyl Ethyl Cyclohexyl Propyl Cyclopentyl Butyl Methylcyclopentyl Hexyl Cyclopentadienyl Octyl Vinylphenyl Decyl lsopropenylphenyl Vinyl Cinnamyl Ally] Naphthyl Ethynyl Propargyl Phenyl Tolyl Xylyl 6 3( 2 5)2 C6H4(CH2 u s Many obvious variations of these radicals will be apparent to those skilled in the art and are included within the scope of the invention.

Substituted hydrocarbon, alkyl, aryl, etc., radicals are considered fully equivalent to the hydrocarbon, alkyl, aryl, etc., radicals and to be part of this invention. By substituted is meant radicals containing substituents which do not alter significantlythe character or reactivity of the radical. Examples are:

Halide (fluoride, chloride, bromide, iodide) Hydroxy Ether (especially lower alkoxy) Ester (especially lower carbalkoxy) Aminoacyl (amide) Amino Nitro Cyano Mercapto Thioether Sulfoxy Sulfone Sulfonic acid ester, amide, etc. In general, no more than about three such substituent groups will be present for each 10 carbon atoms in the radical.

Preferably, the hydrocarbon or substituted hydrocarbon radicals in the compounds of this invention are free from ethylenic and acetylenic unsaturation and have no more than about 30 carbon atoms, desirably no more than about 12 carbon atoms. A particular preference is expressed for hydrocarbon radicals (usually alkyl radicals) containing at least six carbon atoms.

As previously indicated, Y may be halogen (usually chlorine or bromine and preferably chlorine) or SSR. More often, it is SSR. In that event, the two R radicals may be the same or different but they are usually the same.

The compounds of this invention are prepared by reacting a 1,2,4-thiadiazole sulfenyl chloride with a mercaptan:

wherein X is halogen or SZ and Z is halogen. The 1,2,4- thiadiazole sulfenyl chloride used as a reactant may be prepared by first reacting cyanamide with carbon disulfide and a base to form the dipotassium salt of dimercaptocyanamide and then reacting said dipotassium salt with two moles of chlorine to yield 3-chloro- 1,2,4- thiadiazolyl-S-sulfenyl chloride, or with one mole of sulfur followed by two moles of chlorine to yield 1,2,4- thiadiazolyl-3,5-bis(sulfenyl chloride). This reaction is described at Jo'uknal 0f Organic Chemistry, 36, 14 1971 The reaction with the mercaptan is conveniently carried out merely byhadding the mercaptan to the l,2,4- thiadiazole sulfenyl chloride, usually at a temperature below about 20C.; and preferably below 0C. It is usually convenient t'oemploy a non-polar solvent, especially a chlorinated solvent such as methylene chloride, ethylene chloride, chlorobenzene or the like. The course of the reaction may be followed by measuring the hydrogen chloride evolved; when hydrogen chloride evolution has ceased, the reaction may be considered complete. The product may then be isolated by conventional procedures. In most instances, the product is a liquid.

The preparation of the compounds of this invention is illustrated by the following examples. All parts and percentages are by weight.

' EXAMPLE 1 A suspension of parts (0.663 mole) of the dipotassium salt of 3,5-dimercapto-1,2,4-thiadiazole in 526 parts of chloride is reacted with 94 parts 1.325 moles) of chlorine at a temperature between #60? and 55.C. To the resulting chlorinated intermediate is added 194 parts (0.663 mole) of t-octyl mercaptan over 1/2 hour under nitrogen, with stirring. The temperature during the t-octyl mercaptan addition is maintained between 55 and C. The evolved hydrogen chloride is absorbed in a trap containing caustic solution.

When hydrogen chloride evolution has ceased, the methylene chloride is removed by evaporation and the product is dissolved in toluene. The toluene solution is filtered (using a filter aid material) and the toluene is evaporated to yield the desired bis-disulfide which contains 33.57% sulfur and 4.05% nitrogen.

EXAMPLE 2 The dipotassium salt of dimercaptocyanamide (103 parts, 0.53 mole) is suspended in 987 parts of methy' lene chloride and reacted with 78 parts 1.1 mole) of chlorine at a temperature between 60 and 55C. t- Octyl mercaptan, 77.3 parts (0.53 mole), is then added with stirring, under nitrogen, at a temperature between ''l0 and .5C. Theaddition time is'one -half hour. Evolved hydrogen chloride is absorbed in a caustic trap as in Example 1.

ANS hen hydrogen chloride evolution has ceased, the methylene chloridesolution is filtered and the methylene chloride is removed by evaporation to yield the desired disulfide which contains 32.65% sulfur, 8.44% ni trogen and 13.2% chlorine.

By similar methods, l,2,4thiadiazolyl disulfides derived from mercaptans such as 2-ethylhexyl, dodecyl, cyclohexyl, benzyl, B-naphthyl and the like may be prepared.

As previously indicated, the compounds of this in vention are useful as corrosion inhibitors in lubricants. They can be employed in a variety of lubricating compositions based on diverse oils of lubricating viscosity, including natural and synthetic lubricating oils and mixtures thereof. The lubricating compositions contemplated include principally crankcase lubricating oils fdr spark-ignited and compression-ignited internal combustion engines including automobile and truck engines, two-cycle engine lubricants, aviationpiston engines, marine and railroad diesel engines, and the like. However, automatic transmission fluids, transaxle lubricants,. gear lubricants, metal-working lubricants, hydraulic fluids, and other lubricating oil and grease compositions can benefit from the incorporation of the present compounds.

Natural oils include animal oils and vegetable oils (e.g., Castor-oil, lard oil) as Well as solvent-refined or acid-refined mineral lubricating oils of the paraffinic, naphthenic, or mixed paraffinic-naphthenic types. Oils of lubricating viscosity derived from coal or shale are also useful base oils. Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized and interpolymeriz ed olefins (e.g., polybutylenes, polypropylenes, propyleneisobutylene copolymers, chlorinated polybutylenes, etc. alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-( 2-ethylhexyl) benzenes, etc); polyphenyls (e.g., biphenyls, terphenyls, etc.), and the like. Alkylene oxide polymers and interpolymers and cating oils. These are exemplified by the oils-prepared I through polymerization of ethylene oxide or propylene 4 oxide, the, alkyland l ethers of these polyoxyalkylene polymers (eg 1 ethylpolyisopropylene glycol ether having an average molecular weight of 1000, diphenyl ether of polyethylene glycol having a molecular weight of500lOOO-,--die thyl ether of polypropylene glycol'havinga molecular weight of 1000l500, etc.) or monoandypolycarboxylic esters thereof, for example, the acetic acid.esters,,.rnixed C C,, fatty acid esters, or the C Oxo acid diester of tetraethylene glycol. Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, maleic acid; azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, etc.) with a variety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, Z-ethylhexyl alcohol, pentaerythritol, etc.). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelat e, dioctyl phthalate, didecyl phthalate, dieicosylsebac ate, the '2 -e thylhexyl diesteroflinoleic acid dimer, thecomplex ester formed by reactingone mole of sebacic acid with two m'oles of tetraethylene glycol and two moles of. Z-ethylhexanoic acid, and the like. Siliconbased oils such as {the polyalk-yl-, polyaryl-, polyalkoxyor polyar'yloxy-siloxane oils and silicate oils comprise another useful class of synthetic lubricants (e.g., tetraethyl silicate, tetraisopropyl silicate, tetra-(Z-ethylhexyl) silicate, tetra-(4- vmetlfiyl-Z-tetraethyl) silicate, tetra-( p-tert-butylphenyl) silicate, hexyl-(4-methyl-2-pentoxy)-disiloxane, poly(- methyl )-siloxanes, poly( methylphe nyl )-siloxanes, etc.). Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decane phosphonic acid, etc.), polymeric tetrahydrofurans, and the like.

In general, about 0.0520.0 parts (by weight) of the compound of this invention is dissolved in .100 parts of oil to produce a satisfactory lubricant. The invention also contemplates the use of other additives in combination with the products of this inventionl such additives include, for example, detergents and dispersants of the ash-containing or ashless type, oxidation inhibiting agents, pour point depressing agents, extreme pressure agents, color stabilizers and anti-foam agents.

The ash-containing detergents are exemplified by oilsoluble neutral and basic salts of alkali or alkaline earth metals with sulfonic acids, carboxylic acids, or organic phosphorus acids characterized by at least one direct carbon-to-phosphorus linkage such as those prepared by the treatment of an olefin polymer (e.g., polyisobu tene having a molecular weight of 1000) with a phosphorizing agent such as phosphorus trichloride, phosphorus heptasulfide, phosphorus pentasulfide, phosphorus trichloride and sulfur, white phosphorus and a sulfur halide, or phosphorothioic chloride. The most commonly used salts of such acids are those of sodium, potassium, lithium, calcium, magnesium, strontium and barium.

The term basic salt is used to designate metal salts 'vvherein'the'metal is-present in. stoichiometrically larger amounts than the organicaci'd radical-The commonly employed methods for preparing the basic salts involve heating a=mineral*-il solution of an acid with a stoichiometric.excess 'of'anietal neutralizing agent such as the "r'net'al'oxide;hydroxide; carbonate, bicarbonate, or sulfide-ata teri-ipera-tuierabove 50C. and filtering the resulting mass: The useofla promoter in the neutralizationstep to aid the incorporationof 'a large excess of metal likewise is known;- Examples of compounds useful as the promoter include phenolic substances such as phenol, naphthol, alkylphenol, thiophenol, sulfurizedalkylphenol, and condensation products of formaldehyde with a phenolic substance; alcohols such as methanol, 2-propanol, octyl alcohol, cellosolve, carbitol, ethylene glycol, stearyl alcohol, and cyclohexyl alcohol; and amines such as aniline, phenylenediamine, phenothiazine, phenyLB-naphthylarnine, and dodecylamine. A particularly effective method for preparing the basic salts comprises mixing an acid with an excess of a basic alkaline earth metal neutralizing agent, a phenonyl-phosphite,polypropylene (molecular weight 500;)-

lic promoter compound, and a small amount of water substituted. phenyl. phosphite, -diisobutyl-substituted phenyl phosphite, metal thiocarbamates, such as zinc dioctyldithiocarbamatc, and barium heptylphenyl dithiocarbamate; Group 11 metal phosphorodithioates such as zinc clicyclohexylphosphorodithioate, zinc dioctylphosphorodithioate, barium di(heptylphenyl) phosphorodithioate, cadmium dinonylphosphorodithi oate, and the zinc salt of a phosphorodithioic acid produced by the reaction of phosphorus pentasulfide with an equimolar mixture of isopropyl alcohol and n-hexyl alcohol.

It is possible to form the lubricants of this invention by dissolving the various additives, or oil solutions thereof, directly in a mineral oil. However, it is generally rnore convenient and is preferred to prepare additive concentrates containing two or more of the desired additives, and to dissolve these concentrates in the mineral oil to form the final lubricating composition.

Typical lubricating compositions according to this invention are listed in the following table. All amounts listed, except those for mineral oil, are exclusive of oil present as diluent.

Parts by weight B C SAE lOW- mineral oil base Product of Example 1 Product of Example 2 Poly-(isodecyl acrylate) Product obtained by esterifying polyisobutenyl succinic anhydridc with pent-aerythritol and neutralizing residual aciditywith commercial mixture of polyethylene polyamines having 3-7 nitrogen atoms Basic calcium alkylbenzenesulfonatc Basic magnesium alkylbenzenesulfonate Silicone antifoam agent boron compounds, phosphorus compounds, epoxides,

aldehydes, organic acids and the like; and esters of hydrocarbon-substituted succinic acids as described in US. Pat. No. 3,381,022.

Extreme pressure agents, auxiliary corrosion-inhibiting agents, and oxidation-inhibiting agents are exemplified by chlorinated aliphatic hydrocarbons such as chlorinated wax; organic sulfides and polysulfides such as benzyl disulfide, bis( chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipentene, and sulfurized terpene; phosphosulfurized hydrocarbons such as the reaction product of a phosphorus sulfide with turpentine or methyl oleate; phosphorus esters including principally dihydrocarbon and trihydrocarbon phosphites such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentyl phenyl phosphite, dipentyl phenyl phosphite, tridecyl phosphite, distearyl phosphite, dimethyl naphthyl phosphite, oleyl 4-pentylphe- What is claimed is:

l. A lubricating composition comprising a major amount of a lubricating oil and a minor amount of a compound having the formula SCR wherein R is a hydrocarbon radical and Y is halogen or SSR.

2. A lubricating composition according to claim 1 wherein Y is chlorine.

3. A lubricating composition according to claim 2 wherein R is an alkyl radical containing at least 6 carbon atoms.

4. A lubricating composition according to claim 3 wherein R is the t-octyl radical.

5. A lubricating composition according to claim 1 wherein Y is SSR.

7. A lubricating composition according to claim 6 wherein R is the t-octyl radical. 

1. A LUBRICATING COMPOSITION COMPRISING A MAJOR AMOUNT OF A LUBRICATING OIL AND A MINOR AMOUNT OF A COMPOUND HAVING THE FORMULA
 2. A lubricating composition according to claim 1 wherein Y is chlorine.
 3. A lubricating composition according to claim 2 wherein R is an alkyl radical containing at least 6 carbon atoms.
 4. A lubricating composition according to claim 3 wherein R is the t-octyl radical.
 5. A lubricating composition according to claim 1 wherein Y is SSR.
 6. A lubricating composition according to claim 5 wherein R is an alkyl radical containing at least 6 carbon atoms.
 7. A lubricating composition according to claim 6 wherein R is the t-octyl radical. 